I don't think I could do just a top 10 because that would be pretty boring honestly.... Here is a top 15 since it includes some lesser known games as well...

15. Donkey Kong Country Returns- Another excellent platformer for the Wii. The difficulty and the okay 2 player mode hold it back but it was an excellent game nonetheless.14.House of the Dead 2 & 3 Return- Probably the game I've played second most on my Wii, my friend and I used to play this every night. It was my introduction to Rail shooters and the Wii13. Muramasa The Demon Blade- probably the best action game for the Wii and also extremely gorgeous.12.Kirby's Epic Yarn- a beautiful platformer by Nintendo. 11.Little King's Story- the 2nd best RPG for the Wii and other than the PSP port, can once again only be found on the Wii. The game had very modest sales and is truly a Hidden Gem for the console.10. Mario Party 8- A return to form for the Mario Party series and probably the best MP since the original. 9.Dead Space Extraction- Another excellent Rail Gun shooter for the Wii. This game really took advantage of the Wii's hardware.8.Mario Kart Wii- The best online Wii game and a huge seller for the console. This isn't my favorite MK title (a little too chaotic) but it is still really good.7. Sin and Punishment: Star Successor- The best rail shooter on the Wii and the game doesn't get recognized nearly enough.6. Sonic Colors- The best Sonic game in years and being a Wii exclusive was a huge plus.5. New Super Mario Bros Wii- This game signaled the return of 2D platformers and was hugely successful on the console. It was also an excellent multiplayer game game, and started the trend of 4 player platforming action.4.Xenoblade Chronicles- the best RPG of last gen easily, the Wii was pretty starved of AAA RPG's but this game really delivered. A wonderful game.3. Super Smash Bros Brawl- By far, the game I have spent the most time with on the Wii. I have put in thousands and thousands of hours into the game and despite some annoying mechanics and Meta Knight, it was still a really fun game. I think the huge Smash scene in Kansas also helped with my enjoyment of the game.2. Wii Sports- The pack in game for the Wii wasn't the best game but it definitely was one of the the biggest influential games that the generation. The fact that it was a pack in game only helps the game even more. The game is up much higher then I would normally rate it simply based on influence and the number of people who immediately associate the Wii with Wii Sports.1. Super Mario Galaxy 1 & 2- Both are amazing games and while 2 is definitely the stronger of the 2 games, I think both deserve the #1 spot since they were widely successful games for the Wii and were the 2 best 3D platformers of that generation.